Internal gauge



Apm F17, 71%23.

K. LAUER INTERNAL GAUGE Filed No v.

atented Apr. 17, 1923.

UNITED STATES KARL LAUER, @F

PATENT OFFICE.

ESSEN, GERMANY, ASSIGNOB T0 FRIED. KBUPP AKTIENGESELL- SCHAJET, OF ESSEN-UN-THE-RUHB, GERMANY.

INTERNAL GAUGE.

Application med November 29, mm. Serial No. 518,612.

To all whom. it may concern:

Be it known that I, KARL LAUnn', residing at Essen, Germany, a citizen of the German Republic, have invented a certain new and useful Improvement in Internal Gauges, of which the following is a specification.

The present invention relates to internal gauges having an adjustable plunger body and a member angularly displaceable there to provided with a conical surface actuating the plunger. In known gauges of this kind the body rests upon the conical surface, which body is carried in a tight fitting cylindrical boring. Such a construction has the disadvantage, that a wearing away may occur which makes possible a lateral displacement of said body with a consequent error in measurement, which cannot he corrected without renewal of the parts guiding said body. The object of the present in vention is to rnalre impossible such a wearing away through a special type of construction of the above named guiding parts; and secondly to provide a device, which in the simplest manner makes it possible to counteract the unfavorable action of any wear of the guiding parts when constructed in accordance with the present invention.

In the accompanying drawing an embodiment of the present invention is illustrated showing an internal caliper gauge having an indicating lever device and of which:

Fig. l is an elevation of the gauge with a portion broken away;

Fig. 2 an axial longitudinal section thereof;

Fig. 3 a transverse section along line 3-3 of hi 2 seen from the left;

Fig. ltransverse section along line 4.- l of Fig. 2 also seen from the left and Fig. 5 a section along line 5-5 oi Fig. 2 seen from above.

The age hody consists of two tubular parts and A- which are detachably screwed together.

- The part A. is provided with a longitudinal slit on its threaded end engaging the part A and with a tapered thread a over which an internally threaded nut B is screwed. By means of the nut B the slit end of the part A is tightened down over the part A, which makes impossible any unintentional displacement between the two g. ll,

parts A and A. The gage body is provided with an inner thread a in its portion A. into which a sleeve C having a correspond- 1ng exterior thread is screwed (see Fig. 2). Surrounding the sleeve C is arranged a thimble D which is rigidly secured on the sleeve C by means of a set screw 1E and a lock nut 1E. The thimble D fits tightly around the cylindrical end of the gage body portion A. Upon the latter is rovided a millimeter graduation a, while t e thimble D carries circumferential graduations al In the position shown on the drawing the thimble D is set at zero position. A. sleeve (Jr is further provided, which is freely rev-- oluble in the sleeve C, and extends at both ends outside this latter. @n the end of the sleeve G, that reaches be end the sleeve C to the right in Fig. 2, is t readed a housing H of an indicating device. This housing is rigidly connected with the sleeve Gr by means of a set screw J and engages with the end face of the sleeve (3 without play.

The part of the sleeve G that reaches beyond the left-hand end of the sleeve C in Fig. 2, carries a circular stepped extension 9 against which the lett-hand-end-face oi the sleeve C contacts without play, see Fig. 2. The stepped extension 9 also serves as a bearing for the sleeve G in the auge body. A. longitudinal slit 9 is .provied in the extension 9' with which a guiding key a, secured in the gauge hody, engages (see Figs. 2 and 4}. The sleeve may consequently be displaced axially but cannot be turned in the gauge body.

A stepped rod K, partly enclosed loy the sleeve I} is slidably mounted in the gauge body A A This rod reaches into the housing II through a boring it provided the bottom of said housing. A cylindrical stop-piece F0 is rigidly connected with the end of the rod K that reaches into the housing H, the diameter of said stop-piece being greater than the diameter of the horing ii A stud M actuated by a spring, not shown, contacts with the stop-piece it" which stud is connected through a contacting member, likewise not shown, with the pointer N of an indicating device N 91 The stop-piece 70 contacts with the hottoro of the housing H. under the action of a spring P which abuts at one end against a shoulder k on the rod K and at the other end against an inner cylindrical abutment g of the Ill) sleeve G. The cylindrical abutment g forms the end of an enlarged borin g of the sleeve G, the diameter of which ring is somewhat larger than the diameter of the portion of the rod K forming the shoulder is, so that a mutual displacement between the sleeve G and the rod'K is possible;

The end of the rod K which lies to the left in Fig. 2 is conical. Three balls Q rest on this conical surface 70 and a plunger '1, actuated by a spring R, contacts with each of said balls. These lungers T are displaceable perpendicular y to the direction of movement of the rod K. Their work measuring surfaces,'that is their ends it are situated on a circle the diameter of which is the fundamental measure of the gauge, when the thimble D) is in its zero position, see Fig. 3. The balls Q are guided in runways a on the side away from the rod K, which runways are formed by the flat surfaces. a placed at an angle to each other, see in articular Fig. 5. On account of the action of the spring P and the conical surface 70 the balls Q are permanently ke tin contact with the runway surfaces a. ith their halves directed towards the rod K the balls Q rest in half-cylindrical races a The described caliper gauge is intended for measuring bores or counter-bores, the diameter of which is greater then the above mentioned fundamental measure of the gauge, yet not over a certain maximum ran e.

hen a bore is to be measured, the gauge is inserted in the bore with its end carrying the plungers T, and the thimble D turned. The sleeve C, which is rigidly connected with the thimble D is consequently screwed into the gauge bod A A The displacement of the sleeve is communicated to the sleeve G (which latter is secured against turnin by the key a and to the housing H of t e indicating device connected therewith and also to the rod K through the intermedia of the s ring P, the stop k remaining stil in contact with the bottom of the housing H by being actuated by the spring P. Through the axial dis lacement of the rod K, the balls Q as wel as the plungers T are pushed outwards by virtue of the conical surface is. The plungers T will finally come with their measuring surfaces 25 in contact with the walls of the bore to be calipered. As soon as this takes lace 'on further rotation of the thimble the sleeve C and-the housipg H will be dis laced relative to the rod the sprin P being compressed. As a consequence t e stud M connected with the pointer N will be displaced so that the latter will deflect. The turning of the thimble D is then continued until the pointer registers with the zero mark of the and by taking regard to the fundamental of the gauge.

Practically no wear of the guiding means of the plungers T is possible, because axial forces only are transmitted to the plungers T. Further any wear of the guiding means for the balls Q can only cause the formation of new grooves into which the balls Q should necessarily be pressed without side play by the spring P, because they bear permanently, under the action of the spring P and the conical surfaces is, against thefaces a", and this only at one point of each face a. When such a wearing down does occur, the dis tance between the stud M, connected with the pointer N, and the contact pointswith the balls Q is increased, and as a consequence a faulty measurement will be indicated on.

the scales a, d. This may however be corrected in the simplest manner. In this case the caliper gauge is inserted with its plungers T into a ring-gauge; the thimble is thereupon set to the measure corresponding to the diameter of the ring-gauge, the nut B then loosened and the part A screwed further into the part A, until the pointer N indicates zero. The nut B is then tightened and the gauge is again ready for use.

Claims- 1. A calipering device comprising a supporting casing, a ball bearing race in said casing, a ball within said race and a conical actuator mounted in said casing with the axis of the contactin conical face of said actuator at an ang e to the direction of movement of said ball, said ball bearing race being formed by two surfaces which form an angle with each other.

2. A calipering device. comprising a spring pressed caliperin plunger, a supporting casing for said p unger, a ball bearing race in said casing, a ball within said race, and a conical actuator mounted in said casing with the axis of the contacting conical face of said actuator at an angle to the axis of said plunger, the spring of said spring pressed plunger tending to contact said plunger with said ball, said ball bearing race being formed by two surfaces which form an angle with each other.

The foregoing specification signed at Essen, Germany, this 22nd day of October,

KARL LAUER. 

